"use client";

import { useEffect, useState } from "react";
import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
import { Button } from "@/components/ui/button";
import { RefreshCw, Mail } from "lucide-react";
import { useSession } from "next-auth/react";
import { formatDistance } from 'date-fns/formatDistance';
import { fr } from 'date-fns/locale/fr';
import { useRouter } from "next/navigation";

interface Email {
  id: string;
  subject: string;
  from: string;
  fromName?: string;
  date: string;
  read: boolean;
  starred: boolean;
  folder: string;
}

interface EmailResponse {
  emails: Email[];
  mailUrl: string;
  error?: string;
}

export function Email() {
  const [emails, setEmails] = useState<Email[]>([]);
  const [mailUrl, setMailUrl] = useState<string | null>(null);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [refreshing, setRefreshing] = useState(false);
  const { data: session, status } = useSession();
  const router = useRouter();

  const fetchEmails = async (isRefresh = false) => {
    if (status !== 'authenticated') {
      setError('Please sign in to view emails');
      setLoading(false);
      setRefreshing(false);
      return;
    }

    if (isRefresh) setRefreshing(true);
    if (!isRefresh) setLoading(true);
    
    try {
      const response = await fetch('/api/mail');
      
      if (!response.ok) {
        const errorData = await response.json();
        throw new Error(errorData.error || 'Failed to fetch emails');
      }

      const data = await response.json();

      if (data.error) {
        throw new Error(data.error);
      }

      const validatedEmails = data.emails.map((email: any) => ({
        id: email.id || Date.now().toString(),
        subject: email.subject || '(No subject)',
        from: email.from || '',
        fromName: email.fromName || email.from?.split('@')[0] || 'Unknown',
        date: email.date || new Date().toISOString(),
        read: !!email.read,
        starred: !!email.starred,
        folder: email.folder || 'INBOX'
      }));

      setEmails(validatedEmails);
      setMailUrl(data.mailUrl || 'https://espace.slm-lab.net/apps/mail/');
      setError(null);
    } catch (err) {
      setError(err instanceof Error ? err.message : 'Error fetching emails');
      setEmails([]);
    } finally {
      setLoading(false);
      setRefreshing(false);
    }
  };

  // Initial fetch
  useEffect(() => {
    if (status === 'authenticated') {
      fetchEmails();
    } else if (status === 'unauthenticated') {
      setError('Please sign in to view emails');
      setLoading(false);
    }
  }, [status]);

  // Auto-refresh every 5 minutes
  useEffect(() => {
    if (status !== 'authenticated') return;

    const interval = setInterval(() => {
      fetchEmails(true);
    }, 5 * 60 * 1000);

    return () => clearInterval(interval);
  }, [status]);

  const formatDate = (dateString: string) => {
    try {
      const date = new Date(dateString);
      return formatDistance(date, new Date(), {
        addSuffix: true,
        locale: fr
      });
    } catch (err) {
      return dateString;
    }
  };

  if (status === 'loading' || loading) {
    return (
      <Card className="transition-transform duration-500 ease-in-out transform hover:scale-105 bg-white/95 backdrop-blur-sm border-0 shadow-lg h-full">
        <CardHeader className="flex flex-row items-center justify-between pb-2 border-b border-gray-100">
          <CardTitle className="text-lg font-semibold text-gray-800">
            <div className="flex items-center gap-2">
              <Mail className="h-5 w-5 text-gray-600" />
              <span>Courrier</span>
            </div>
          </CardTitle>
        </CardHeader>
        <CardContent className="p-6">
          <div className="flex items-center justify-center">
            <RefreshCw className="h-5 w-5 animate-spin text-gray-400" />
          </div>
        </CardContent>
      </Card>
    );
  }

  return (
    <Card className="transition-transform duration-500 ease-in-out transform hover:scale-105 bg-white/95 backdrop-blur-sm border-0 shadow-lg h-full">
      <CardHeader className="flex flex-row items-center justify-between pb-2 space-x-4 border-b border-gray-100">
        <CardTitle className="text-lg font-semibold text-gray-800">
          <div className="flex items-center gap-2">
            <Mail className="h-5 w-5 text-gray-600" />
            <span>Courrier</span>
          </div>
        </CardTitle>
        <Button
          variant="ghost"
          size="icon"
          onClick={() => fetchEmails(true)}
          disabled={refreshing}
          className={`${refreshing ? 'animate-spin' : ''} text-gray-600 hover:text-gray-900`}
        >
          <RefreshCw className="h-4 w-4" />
        </Button>
      </CardHeader>
      <CardContent className="p-3">
        {error ? (
          <p className="text-center text-red-500">{error}</p>
        ) : (
          <div className="space-y-2 max-h-[220px] overflow-y-auto">
            {emails.length === 0 ? (
              <p className="text-center text-gray-500">
                {loading ? 'Loading emails...' : 'No unread emails'}
              </p>
            ) : (
              emails.map((email) => (
                <div
                  key={email.id}
                  className="p-2 hover:bg-gray-50/50 rounded-lg transition-colors cursor-pointer"
                  onClick={() => router.push('/mail')}
                >
                  <div className="flex items-center justify-between mb-1">
                    <span className="text-sm text-gray-600 truncate max-w-[60%]" title={email.fromName || email.from}>
                      {email.fromName || email.from}
                    </span>
                    <div className="flex items-center space-x-2">
                      {!email.read && <span className="w-1.5 h-1.5 bg-blue-600 rounded-full"></span>}
                      <span className="text-xs text-gray-500">{formatDate(email.date)}</span>
                    </div>
                  </div>
                  <p className="text-sm text-gray-800 truncate">{email.subject}</p>
                </div>
              ))
            )}
          </div>
        )}
      </CardContent>
    </Card>
  );
} 